/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.catalina.tribes.group;

import org.apache.catalina.tribes.Channel;
import org.apache.catalina.tribes.ChannelException;
import org.apache.catalina.tribes.ChannelMessage;
import org.apache.catalina.tribes.ChannelReceiver;
import org.apache.catalina.tribes.ChannelSender;
import org.apache.catalina.tribes.Member;
import org.apache.catalina.tribes.MembershipService;
import org.apache.catalina.tribes.MessageListener;
import org.apache.catalina.tribes.UniqueId;
import org.apache.catalina.tribes.membership.McastService;
import org.apache.catalina.tribes.transport.ReplicationTransmitter;
import org.apache.catalina.tribes.transport.SenderState;
import org.apache.catalina.tribes.transport.nio.NioReceiver;
import org.apache.catalina.tribes.util.Arrays;
import org.apache.catalina.tribes.util.Logs;

/**
 * The channel coordinator object coordinates the membership service, the sender
 * and the receiver. This is the last interceptor in the chain.
 * 
 * @author Filip Hanik
 * @version $Revision: 532943 $, $Date: 2007-04-27 11:14:58 +0800 (星期五, 27 四月
 *          2007) $
 */
public class ChannelCoordinator extends ChannelInterceptorBase implements
		MessageListener {
	private ChannelReceiver clusterReceiver = new NioReceiver();
	private ChannelSender clusterSender = new ReplicationTransmitter();
	private MembershipService membershipService = new McastService();

	// override optionflag
	protected int optionFlag = Channel.SEND_OPTIONS_BYTE_MESSAGE
			| Channel.SEND_OPTIONS_USE_ACK
			| Channel.SEND_OPTIONS_SYNCHRONIZED_ACK;

	public int getOptionFlag() {
		return optionFlag;
	}

	public void setOptionFlag(int flag) {
		optionFlag = flag;
	}

	private int startLevel = 0;

	public ChannelCoordinator() {

	}

	public ChannelCoordinator(ChannelReceiver receiver, ChannelSender sender,
			MembershipService service) {
		this();
		this.setClusterReceiver(receiver);
		this.setClusterSender(sender);
		this.setMembershipService(service);
	}

	/**
	 * Send a message to one or more members in the cluster
	 * 
	 * @param destination
	 *            Member[] - the destinations, null or zero length means all
	 * @param msg
	 *            ClusterMessage - the message to send
	 * @param options
	 *            int - sender options, see class documentation
	 * @return ClusterMessage[] - the replies from the members, if any.
	 */
	public void sendMessage(Member[] destination, ChannelMessage msg,
			InterceptorPayload payload) throws ChannelException {
		if (destination == null)
			destination = membershipService.getMembers();
		clusterSender.sendMessage(msg, destination);
		if (Logs.MESSAGES.isTraceEnabled()) {
			Logs.MESSAGES.trace("ChannelCoordinator - Sent msg:"
					+ new UniqueId(msg.getUniqueId()) + " at "
					+ new java.sql.Timestamp(System.currentTimeMillis())
					+ " to " + Arrays.toNameString(destination));
		}
	}

	/**
	 * Starts up the channel. This can be called multiple times for individual
	 * services to start The svc parameter can be the logical or value of any
	 * constants
	 * 
	 * @param svc
	 *            int value of <BR>
	 *            DEFAULT - will start all services <BR>
	 *            MBR_RX_SEQ - starts the membership receiver <BR>
	 *            MBR_TX_SEQ - starts the membership broadcaster <BR>
	 *            SND_TX_SEQ - starts the replication transmitter<BR>
	 *            SND_RX_SEQ - starts the replication receiver<BR>
	 * @throws ChannelException
	 *             if a startup error occurs or the service is already started.
	 */
	public void start(int svc) throws ChannelException {
		this.internalStart(svc);
	}

	/**
	 * Shuts down the channel. This can be called multiple times for individual
	 * services to shutdown The svc parameter can be the logical or value of any
	 * constants
	 * 
	 * @param svc
	 *            int value of <BR>
	 *            DEFAULT - will shutdown all services <BR>
	 *            MBR_RX_SEQ - stops the membership receiver <BR>
	 *            MBR_TX_SEQ - stops the membership broadcaster <BR>
	 *            SND_TX_SEQ - stops the replication transmitter<BR>
	 *            SND_RX_SEQ - stops the replication receiver<BR>
	 * @throws ChannelException
	 *             if a startup error occurs or the service is already started.
	 */
	public void stop(int svc) throws ChannelException {
		this.internalStop(svc);
	}

	/**
	 * Starts up the channel. This can be called multiple times for individual
	 * services to start The svc parameter can be the logical or value of any
	 * constants
	 * 
	 * @param svc
	 *            int value of <BR>
	 *            DEFAULT - will start all services <BR>
	 *            MBR_RX_SEQ - starts the membership receiver <BR>
	 *            MBR_TX_SEQ - starts the membership broadcaster <BR>
	 *            SND_TX_SEQ - starts the replication transmitter<BR>
	 *            SND_RX_SEQ - starts the replication receiver<BR>
	 * @throws ChannelException
	 *             if a startup error occurs or the service is already started.
	 */
	protected synchronized void internalStart(int svc) throws ChannelException {
		try {
			boolean valid = false;
			// make sure we don't pass down any flags that are unrelated to the
			// bottom layer
			svc = svc & Channel.DEFAULT;

			if (startLevel == Channel.DEFAULT)
				return; // we have already started up all components
			if (svc == 0)
				return;// nothing to start

			if (svc == (svc & startLevel))
				throw new ChannelException("Channel already started for level:"
						+ svc);

			// must start the receiver first so that we can coordinate the port
			// it
			// listens to with the local membership settings
			if (Channel.SND_RX_SEQ == (svc & Channel.SND_RX_SEQ)) {
				clusterReceiver.setMessageListener(this);
				clusterReceiver.start();
				// synchronize, big time FIXME
				membershipService.setLocalMemberProperties(getClusterReceiver()
						.getHost(), getClusterReceiver().getPort());
				valid = true;
			}
			if (Channel.SND_TX_SEQ == (svc & Channel.SND_TX_SEQ)) {
				clusterSender.start();
				valid = true;
			}

			if (Channel.MBR_RX_SEQ == (svc & Channel.MBR_RX_SEQ)) {
				membershipService.setMembershipListener(this);
				membershipService.start(MembershipService.MBR_RX);
				valid = true;
			}
			if (Channel.MBR_TX_SEQ == (svc & Channel.MBR_TX_SEQ)) {
				membershipService.start(MembershipService.MBR_TX);
				valid = true;
			}

			if (!valid) {
				throw new IllegalArgumentException(
						"Invalid start level, valid levels are:SND_RX_SEQ,SND_TX_SEQ,MBR_TX_SEQ,MBR_RX_SEQ");
			}
			startLevel = (startLevel | svc);
		} catch (ChannelException cx) {
			throw cx;
		} catch (Exception x) {
			throw new ChannelException(x);
		}
	}

	/**
	 * Shuts down the channel. This can be called multiple times for individual
	 * services to shutdown The svc parameter can be the logical or value of any
	 * constants
	 * 
	 * @param svc
	 *            int value of <BR>
	 *            DEFAULT - will shutdown all services <BR>
	 *            MBR_RX_SEQ - starts the membership receiver <BR>
	 *            MBR_TX_SEQ - starts the membership broadcaster <BR>
	 *            SND_TX_SEQ - starts the replication transmitter<BR>
	 *            SND_RX_SEQ - starts the replication receiver<BR>
	 * @throws ChannelException
	 *             if a startup error occurs or the service is already started.
	 */
	protected synchronized void internalStop(int svc) throws ChannelException {
		try {
			// make sure we don't pass down any flags that are unrelated to the
			// bottom layer
			svc = svc & Channel.DEFAULT;

			if (startLevel == 0)
				return; // we have already stopped up all components
			if (svc == 0)
				return;// nothing to stop

			boolean valid = false;
			if (Channel.SND_RX_SEQ == (svc & Channel.SND_RX_SEQ)) {
				clusterReceiver.stop();
				clusterReceiver.setMessageListener(null);
				valid = true;
			}
			if (Channel.SND_TX_SEQ == (svc & Channel.SND_TX_SEQ)) {
				clusterSender.stop();
				valid = true;
			}

			if (Channel.MBR_RX_SEQ == (svc & Channel.MBR_RX_SEQ)) {
				membershipService.stop(MembershipService.MBR_RX);
				membershipService.setMembershipListener(null);
				valid = true;

			}
			if (Channel.MBR_TX_SEQ == (svc & Channel.MBR_TX_SEQ)) {
				valid = true;
				membershipService.stop(MembershipService.MBR_TX);
			}
			if (!valid) {
				throw new IllegalArgumentException(
						"Invalid start level, valid levels are:SND_RX_SEQ,SND_TX_SEQ,MBR_TX_SEQ,MBR_RX_SEQ");
			}

			startLevel = (startLevel & (~svc));

		} catch (Exception x) {
			throw new ChannelException(x);
		} finally {

		}

	}

	public void memberAdded(Member member) {
		SenderState.getSenderState(member);
		super.memberAdded(member);
	}

	public void memberDisappeared(Member member) {
		SenderState.removeSenderState(member);
		super.memberDisappeared(member);
	}

	public void messageReceived(ChannelMessage msg) {
		if (Logs.MESSAGES.isTraceEnabled()) {
			Logs.MESSAGES.trace("ChannelCoordinator - Received msg:"
					+ new UniqueId(msg.getUniqueId()) + " at "
					+ new java.sql.Timestamp(System.currentTimeMillis())
					+ " from " + msg.getAddress().getName());
		}
		super.messageReceived(msg);
	}

	public ChannelReceiver getClusterReceiver() {
		return clusterReceiver;
	}

	public ChannelSender getClusterSender() {
		return clusterSender;
	}

	public MembershipService getMembershipService() {
		return membershipService;
	}

	public void setClusterReceiver(ChannelReceiver clusterReceiver) {
		if (clusterReceiver != null) {
			this.clusterReceiver = clusterReceiver;
			this.clusterReceiver.setMessageListener(this);
		} else {
			if (this.clusterReceiver != null)
				this.clusterReceiver.setMessageListener(null);
			this.clusterReceiver = null;
		}
	}

	public void setClusterSender(ChannelSender clusterSender) {
		this.clusterSender = clusterSender;
	}

	public void setMembershipService(MembershipService membershipService) {
		this.membershipService = membershipService;
		this.membershipService.setMembershipListener(this);
	}

	public void heartbeat() {
		if (clusterSender != null)
			clusterSender.heartbeat();
		super.heartbeat();
	}

	/**
	 * has members
	 */
	public boolean hasMembers() {
		return this.getMembershipService().hasMembers();
	}

	/**
	 * Get all current cluster members
	 * 
	 * @return all members or empty array
	 */
	public Member[] getMembers() {
		return this.getMembershipService().getMembers();
	}

	/**
	 * 
	 * @param mbr
	 *            Member
	 * @return Member
	 */
	public Member getMember(Member mbr) {
		return this.getMembershipService().getMember(mbr);
	}

	/**
	 * Return the member that represents this node.
	 * 
	 * @return Member
	 */
	public Member getLocalMember(boolean incAlive) {
		return this.getMembershipService().getLocalMember(incAlive);
	}

}
